Telephone repeater system.



'N. G. WARTH. TELEPHONE BEPEATBR SYSTEM; APPLICATION FILED JULY 15, 1907 978,083; Ptented Dec. 6; 1910.

M I 5 I v ahwwboz fi 1?. M Mr W Agatha neg;

To all whom it may conccmr a citizen of the United States,-residing at v .Columhus,

State of Ohio, have invented a certain new 'and useful lmprovement in Telephone Re-- UNITED STATES: PATENT OFFICE,

imrnamnn GLW RTH, or coLuiasus, OHIO.

TELEPHONE anrna'rnn 's 'scrnm.

Be it known that I, NATHANIEL G. 'WAR'rH,

in the county of Franklin and -peater Systems, of which the-following is a slmplified, efficient and economical character for long distance or dlflicult transmlss on specification, p

The .obg'ctof the invention. is to provlde a system 0' heretofore impossible with original transmission, whereby an enfeehle or. attenuated inltial "or repeated telephonic current may be reproduced and retransmltted wlthmcreased power by the intermediate station repeaters of a line circuit and thus obtaining a duplication at the distant receiver of the originating actuating sounds with the accuracy and volume usual with single direciprocally as a root transmission. I

This lnve'nt-lon is directed more speclfiwhy to the type of apparatus and arrange ment o-fcircuits wherein two repeater 1nstrumentalities are used cooperatively and repeater at each repeatng point on a circuit, and. the transmission for each telephonic impulse is wholly rogressive or unidirectional, and not divlded or bidirectional from the repeaters. Repeating systems of the divided or bidirectional transmission class as at present in'commer --c1al use are deficient fortransm ssion reuiring two -'or more retransmissions. In t e two-wayor bldlrectional retransmission, of the PllOI' art, the first repeaterywhen two are connected in aline, (each repeater em-' 40 b racing a single repeater apparatus) .is fcaused to be operated by the backward, current as it is by the original currents which. produces a mere confuslon of 1nart1eulate v sounds and precludes such'extra-long range 45,

transmission or service as is herein vcontemplated. The unidirectional transmission secured in my. system is prod-uced by the the repeater nearest first repeater, that is,

the then-transmitting station. relaying .the

effects into the associatedcireuit only and thoseeffects the second repeater relaying only, thence into its next associated circuit to the .then receiving station or. telephone or to a similarly operating" repeater in the circuit and then to the The weII-knOWn JJnaturaI flattening or dis:

7 circuits and associated automati-. .cally reciprocating repeater apparatus of the receiver windin actions involved terminal telephone. 1

Speclflcation otI-ettci's Patent. Patented Dec.6, 1910. Application alea'aul s, 1907.- Serial No. asaaaa tortion of the form of the wave due to cir- "cuit retarding efiz'ects and losses revents, of course,rin practice, a considera le number of retransmissions, but as, several retransmissions are necessary or desirable my systern makes feasible the extension of retrah's mission byplural repeating stations.

- The 0 eration of my repeaters is such that each in ividual repeater lnstrumentat each repeater station receives the weakened initial currents-from its respective line or circuit section, reproduces the currents withfexactness and augmented volume and retransmits them into the associated line circuit with the full energy. set, up by the transmitter. Each repeater com rises a receiver and a transmitter assemb ed in repeater relation and both elements are included in local cir. cuits in inductive relation to the line cir- -cuits. Each receiver, in addition toactuating its transmitter to send currents into the associated line circuit, has means within its local circuit to avoid any actuationof its transmitter by currents set up locally b either repeater, thereby reventing sel act-ion. This seeming para oxical condition of the receiversbeing sensitive to currents induced from the lineyet insensitive to thelocal currents consequently set up, is pro-- duced by the circuit arrangement and association'of the apparatus, wherein each receiver is sub'ect to the action of two electrically'or inductively balanced local circuits in which the magnetic or inductive action effects are counter-balanced or madeneutral and are also unbalanced and effective to actuate the transmitters.

The unbalanced effect is made possible by directing the received currents sothat they will cooperate in their inductiveefi'ectn ons, while the neutra or counter-balanced e recting the renewed currents so the willflow or act differentially in the ba ancedlocal circuits and windings controlling the receivers -The renewed currents when 0 crating-to create the neutral eifect for t e receivers are operatively actu'pon induction coil secondary windinus'in. the line circuits. A more detailed description of the local eflects and will follow in explaining Figures .1 and 2 The purpose of placing the receiversgin local circuits s tomaintain the, necessary balances, as explained above, and mainta n. them in a state so u set is produced by di-' directed to inductive! -and co v independent of the Q both receiver circuitsoerate the receiver.

main circuits, whereas in all repeater systems in which the balance against the reproduced currents is located in the line circuits are deficient because an unbalanced '5 condition within a inain circuit section or between the circuit sections vwill produce the 'self actiojn resulting in the continuous sound termed howling. In this system a high state of eflic iency is attained by utilizing all induction andbal ancing coils as active and effective factors "-in adding to' the induced retransmitted currents or to the induced effects upon the receivers. Hence there is no dissipati'onof .15 current or loss in effect in mere resistances,

inductances'and capacities, or in derived or artificial circuits as required'and used only for balancing localor main circuits of various kinds in the other systems.

The specific improvements in the above enumerated circuits and apparatus will be.

yet permitting the'm'to be physically joined for economyinwiringor in being connected up forcomposite serv1ce.'. .The prlmary or transmitter circuits. arev also bridged together, the bridgeconnection embracing a battery common to the two transmitters 40 Fig. 2 is a diagram of a modified ,fornr'of the arrangement of circuits and apparatus shown in Fig. l, the line and local. receiver circuits being shown physically separated,-

each' receiver circuit controlling a -respectlve receiver WlIlClll'lg, whereas, in Flg. 1'

ywindings in common. T e primary circuits of the modified arrangement are also physically separated, each clrcuit'bemg provided the preferred embodiment ofthe system, L and L designate the line or main circuit sections, and as all-the repeater apparatus and circuits proper are shown in the view, the equipping of the main circuit conductors WV, WV and'W WV with cords, plugs and auxiliary switching appliances would at once constitute'the arrangementa repeater.

within a cord-circuit. Thc'line circuit sections are divided andmade distinctive by; the bridge conductor .In the main circuit conductors W,-W W and TV? "are included the secondary windings C, C (rand C respectively, of a composite induction winding or windings of. receiver T.

.ceiver, and includedlin this circuit P withthe an induction or an electrical balance to pre:

getherfor unidirectional transmission. This with an individual battery or current supply. Referring particularly to Fig. 1, WhlCl'l is .-The;transmitters-5M twin repeatersare eachincluded 1r'1"a pr1-' jv maiyc rcult, yyhlch circints arez dlstln'ct from .twoprimary circuits, their transmitters-a; p

their-lnductlon co l prlm'arv wmdmgs'ara 13 coil, or each such division-may be the sec ondary winding of a small. induct-ion coil.'- I It designates a repeater device composed of an'electro-magnetic receiver T and a variable resistance transmitter Mysaid repeater device being associated by '1ne.a'ns. of third or 'tertiary windings with the secondary'windings C and G3, which are identified with the line circuit section L.- These tertiary wind-i i'ngs" are connectedin a local or tertiary cir- 75 cuit P in which circuit is also included the .An auxiliary or balancing tertiary circuit P .is likewise connected in circuit witlrthe rereceiver is the secondary winding of anauxillary induction- 0011 C. The function of this c011 1s] two-fold.v F1rst-,'to createone-half oi vent the receiver '1 from actuating its transmitter M iwhen currents are benig' transmitted into. circuit section L, and second, to I cooperate'with tertiary windings C and C for inward. induced currents from circuit section Lto operate-the repeater R. The I two tertiary circuits, or, "considering them jointly, the two halvesof the receiver-circuit, are separatedand made distinctive by I the bridge connection H in which the winding of receiver T is included.' I

The associated repeater R is likewise com posed of a receiver. designated T and a transmitter designated Mfiand is associated with its particular circuit section. If by meansofthird or tertiaryiwindings, through the secondary windings C and C Likewise these tertiary windings are connected in aloca'l circuit or. half circuit P? with-the receiver Tf .Also, as in theopp osite side,

an. auxiliary or'balancing tertiary circuit P is connected in circuit-withit-he receiver, and also in this circuitor half:circuit is-included the secondary. .windi ng of :an auxiliar iln- .duction coilO. The functions of coil tare identical withz those of inductionpoili C, 11p... that .is, it sets up in its-circuit? currents that balance those in its twin local circuit P and creates an electricalorsinduction balance for preventing the receiver 'T from actuating its. transmitter- M "whe'n reproduced currents are beingtransmitted into circuit sectionL", and 'co'i'lC -also coiiper -j ates with tertiary windings? and Cai 1-{ j sponse toinward induced currents from eir-" 'cuitsection L to operate-therepeater- R Thetwo tertiary circuits P and 'Ptfas in the opposite-side, are made distinctive-by the separating LbridgeB-cOnnectibn; H: in which the windingo'f'receiver:'B is included. I

d M -iofi both the -2 v te'r'M is connected in the associated with a'battery B, which is common to both primary circuits. This battery should be 0 low internal, resistance and possess suiiicient electro-motive force and quantity to meet the demands of both transniitter circuits in their parallel relationship. The transmiter M is connected in the primarycircuit designated B and the transmitprimary circuit designated B In the circuit B are.the primary windings of induction coils C C and O and also inductance coil I all in series relation. In the circuit B are likewise connected the primary windings of induction coils C, C and C coil I. The function of the inductance coils I and I is to prevent reaction or cross-talk between the two primary circuits by reason of their common battery physical association and also to regulate the common battery current supply.

'lhecircuits ma be traced and the opera tion described as ollows: The arrows indicate the different currents and .the direction of the current flows. The slender solid arrows designate the initial line currents to be reproduced; The heavy solid arrows designate the constant directionof the primary currents set up bythe comnlon battery in each primary circuit. These latter arrows also indicate the direction of one phase of an inward induced current when set up inthe primary-circuits by the line circuit secondary windings, An inward initial line current or impulse in circuit section or line L, traverses. conductorflV from ri ht to left, terminates at bridge conductor and returns to the originating instrument by 40 Way of conductor W Thi impulse in traversing the secondary windings C and C in the circuitlsets up induced currents in'the associated rimary and tertiary windin s, as ind'icated by.the arrows for local circuits P, :P and B. In tlie primary circuitB current" and. the induced 1 current are shown, in this instance as flowing in the same direction, by the so arrows. It will be noted that'the id heavy receiver T of repeater R will be energized by cooperating current flows in both tertiary cir-.

. cuits, and that the tertiary windings G and Oi cotiperatei'n circuit F". q current in "circuit P, which by the secondary windings of coils C and (3* acting coo eratively to induce into circuit QB,- isrei-n' uced, setting up a current in cir-- feet in energizing receiver I T.

is first induced 'cuit P,. which current cooperates with the current in circuit P'f and freinforcesbthe ef- A current of opposite phase will. produce like effects but. of reverse ,directionin current flows.

The action of the superposed "induced curj rents overfthe primary battery currents uponnthecoiL .O =,will begregular in eii'ect',-

as the 'the coil is merely one-of and the inductance The reinduced duction coils are in a similar magnetic condition' roduced by the same batter current. are, of course, is to be exercised in this connection and in relation to the setting up of the'outward inductive effects in the transmitter circuits not to have the inductioncoil cores too strongly magnetized by the battery. The variation in the existing magnetic state is not effective with a saturated or densely magnetized core, for the reason that both the induced currents and the transmitter currents, especially the former, are incapable of effecting any great variation of a very strong residual field, and any variation produced in the flux lines would notat any time carrythe magnetizw tion much, if any, below the point of saturation. Hence the actions in both respects will be more eflicient and sensitive when the battery is not suflicientto set up a saturated magnetization of the induction coil cores.

. The cooperation of the currents set up, as shown, by the three induction coil. windings in circuits P and P results in a very ef-' fective action in the repeater. The actuation of transmitter'li P in this manner sets up a current in its primary windings which are inductively associated with the opposite Or L line circuit section. The flow of this current is traceable as follows: from the positive pole of battery B through bus conductor'k'to the right, through inductance coil Lprimary of induction coil 0, primary of induction coil C, primary of induction coil Cfflti'ansmitter M bus conductor N, to the negative pole of the battery.- This primary' reproduced current; induces a current in the associated main and local circuits. The current induced into the line section L is a reinforced duplicate of the initial current received from line section L and is thus. retransmitted to the receiving instrument or station or to another intermediaterepeater. The current induced into the tertiary 'circuits P and :P through the tertiary windings C, (3 and the counter current in sec-' ondary winding of coil C, is to create in those circuits for receiver T of repeater R an inactive state by differential current flows.

The current induced into the two windings associated with (the primary windings of coils C and (J is opposite in direction to the flow in the primaries. These induced currents are designated byftll eblOkt-BILIII'IOVS shown in connection with line circuit- L and tertiary circuits P and PE. The current in-v duced into line circuit L is from left to right th'egnext station. .The arrangement of the induction.: coil windings for both repeater tertiary e rcuitsis such that-the inductive 1-25 in conductor W, terminatin'g"at bridgecomductor H andvtraversing conductor W to currents in the two circuits, namely, P with relation to P and I with relation to P are respectively alike or of equivalent value. Thus the induced current n P? from the C Hence the currents in the two circuits, being caused to flow diflerentially, an equalized and neutral effect is produced for the. receiver T. The severalwindings are similar to those described in connection with repeater R but as the inducing current in this instance is in the primary circuit B the flow in the secondary and tertiary windings of the line coils is the same in direction, and. the flows in the two tertiary circuits are opposed and not coiiperati've as when used inreceiving; thus there is no current flow or.

difference of potential in the bridge H and no efiect is produced upon the receiver to actuate the transmitter, resultingin an absence of reaction from local effects or 'rc-' transmission and effectlng a reproduction of the currents without interference. It-will be manifest that a reversalin the transmis sion over the line circuitswill produce automatic reciprocal effects in the twin repeaters; that there is no current. induced into circuit L when circuit L is the receiv ing side, and that no current will beinduced into circuit L when L is the receiving side.

i 1, with modified circuit details. The main circuit sections in this instance are shown physicallyseparated as well as operatively distinct. The two tertiary circuits forv each repeater are also physically separated. as well as operatively distinct. The respective windings for the receivers are shown d.i-'

vided and-one coil or helix apportioned to each pole. This is so shown merely for clear- I ness, as the windings maybe arranged to The induction coil windings in this View, are.

have a helix on each pole for each circuit,

reduced in number but should have equal; and relative values for each circuit, asset. forth in conncctioir with Fig. 1. Each primary circuit is independent, havinganindividual. battery or current supply. ,gTh'e operation is essentially the same as in the Y, 55'

first arrangement and may bebriefiydescribed as follows: An'initial current-in section L will tlow' inward, as 'designatedby the arrows, by wayof conductor VV through the secondary windin of induction cone thence out by way otconductor' This current sets up induced local effects in ,thea

source, into primary circuit B These tertiary currents flow as designated by the ar-- rows and cohperate in operating receiver T of repeater R The operationof repeater R sets up a current from battery B* in primary' circuit 13*, reproducing the orlginating currentswith renewed power; The current in passing through the primary windings of induction coils .O and C induces the reproduced currents into the-secondary windings of the coils, whence it is transmitted to the next-repeater or terminal station. The inducing current in primary circuit B also sets u a current in tertiary circuit P throng the tertiary winding of coil C, and a correspondingcurrent is set up in tertiary circuit P through the-secondary winding] of coil CF. These induced currents in the ter. tiary circuits flow differentially to produce a neutral effect for the receivenas in the arrangement shown in Fig. 1. In the modified arrangement the current flows in opposite directions through two coils of receiver T,

which coils, being equal iniindu'ctive efi'ect,

produce the neutral or inert state by counter I elect-ro-magnetic action.

What I claim as new and desire to secure by Letters Patent is:

- 1. In a reciprocal telephonic repeating system,the combination of adivided "main telephoneci'rcuit having independent induction j .coil secondary-windings in each division, differentially controlled repeating devices, one device for each main'circuit, divided local or tertiary circuits and a'primary circuit for each main circuit, each repeating device heing connected into itsrespective tertiary circuits and' respectively associated inductively with its main circuit secondary windings, primaryjwindings in each primary circuit associated with said secondary windings, a

battery or current supply and a transmitter in each primary circuit, each transmitter being actuated from its respective main circuit and operating to "transmit into the next associated'circuit only, together with means within the tertiary circuits 'for rendering each repeating device operative by its re- 'spective inducingline currents and inoperative by thereproduced currents set up by the oppositeor associated repeating device.

2. In a reciprocal telephone repeating sys tern, the combination of atelephone-line comprising :operatively independent circuit" sections,,.secondary induction coil windings connected 'in 'each section, divided. tertiary and primary windings and. respective diindiictively associated =with their respective lceforeachline circuit section, each repeat- 1I-1g dV10e be1I1g connected in a respective tertiary circuit or tertiary circuit divisions, 1

-- li ne sections, an independent repeating devided-terltiary and primarycircuits therefor .1o' uPP,

transmitter of the opposite repeating device iQS-ficircuits of cat arenas B which provide for differential current flows or, equivalent neutralizing counter-action in the repeating devices to the reproduced currents, anauxiliary induction coil secondary winding connected in one side or circuit of each divided tertiary circuit, and'a primary to saidwinding being connected in the respectiveprimary circuit with said main circuit primary windings, a battery or current 'y for each primary circuit and the included in said primary circuit, whereby each repeating device is operated to repeat by the received induction currents fromits respectivecircuitsection and retransmits the initial'currentswith renewed force into the next circuit section, and the oppositeor reciprocating' repeater device is nptfopera ted .by such reproduced currents, thus" preventzo ing self-reaction and securing-;,unidirectionalreciprocal retransmission.

. '3. In a telephonic repeating system, the

combination of a telephone mam circuit consistmg of independent circuit sections, an

a independent repeating rela .for eachsection,

the relapslieing controlled y'both cooperatin qiipposmg electro-magnetic actions, in' ependent induction-coil secondary windin'each main circuit section, primary aagand tertiarywindings associated with said secondary windings or each relay, primary and tertiary circuits forv said primary and tertiary wmdi'ngs, the respective tertiary 1 'windings beingl 1n their respective tertiary "battery inc'luded'in each prima circuit, the transmitter in each case control ing the outcurrents in the o posite main and ter-- V tial'yclrcuits, an auxl iary or balancing 1n- I410 ductiony-tco l, secondary wind ng for each f relay the respective tertiary windmgs of the "lna'in'circuit induction coils operatin the respective relays by the induced inwar cur.-

' =rei1tsr:= from'-theirrespective circuit sections, andthe re eated or' outward currents energi'zingsai tertiary'windings being opposed m theirefl'ect uponthe receivers by the cur rents set up' inthe auxiliary induction coils, thereby producing a'neutral efli'ect and preto venting self reactlon.

4 I 4. In a telephonic repeating system, the combination with a main line secondary circuitand .a primary repeater circuit, of a repeating device, two local or. tertiary cir- 55. cults, each connected with the repeating device, one of said local or tertiary circuits being directly inductively connected with the main line secondary circuit'and with the primary repeater circuit, and e other local or tertiary circuit being direc y inductively connected-with the primary repeatercircuit only. .t 5. In a telephone, repeating system, the

'combination with a main line circuit and repeater local circuitswefla' repeating prianother {of 'sai relay, a transmitter and a -m'entioned repeating evice;

' combination- 0 a telephone line and relays,

ceivers and prevent reoperation and self "mary' circ'iiit i containing 'abattery and a transmitter-land also containing separate primary induction coil windings, one of said 4 windings. being inductively connected with one of said repeater local circuits only and 7 0 windings being inductively connectd, with another of said repeater local circuits andtwith the main line circuit. 6, In a: telephone ,repeater' system, the

combination -'w1 th a line circuit and a primary circuit,'of a'r'e ating device having two-windings, one c said windings bein inductively connected with ,said lme and primary c rcuitsan'd theotlier of said'windmgs being inductively connected with the gopea-ting devices one 0 which '15 associated with said local circuits, one of the local cir-'- cuits being inductively"connected'with the v line and rimary circuit from the -other re peating tliavice, and the second' 'local circuit being inductively connected with said mary circuit, the, transmitter ofv the mentioned repeating device being connected in circuit Wlth therimary ,0 said last- 9. In "a tele hone repeating-system, the

said line being divide into independent circuit sections by relay stations, two relays at each relay station, one for eachcircuit section, two local or tertiary'circiiitsfor each relay, in which tertia circuits received induced currents from t e line circuit section cooperate to actuate theirirespe'ctivetransmitters, a primary circuit assoclatedwlth 'each relay transmitter,-each primarvcircuit being in inductive connectionwith the opposite line circuit; section and with "both op osite tertiar circuit;s, .;the actuation of eit er transmit r inducing currents into the opposite line section and als'o'i'nducing currents in each of the opposite'tertlary circuits, which transmitter currents m the opposite; tertiary circuits set up 0 posing e ectro-magnetic effects 1n 'the re ay reaction. 10. In a telephone. repeating system ';the combination of a repeating device, two-local circuits with which the repeating device is connected, a-main line circuit and a pri mary -e1rcuit,"one of the local circuits beingfasc 1 inductively connected with the line circuitand the other local circuit-being inductively connected with the primary circuit. v 11. In a' telephone repeater system, the

- combination with a main telephone circuit and a primary circuit therefor, of a repeating device and two local circuits associated with and controlling the repeating device, one: or said local circuits being inductively connected with the main telephone circuit and its primary circuit, and the other local circuit being inductively connected "with vsaid primary circuit only, each inductive connection bemg the inductive equivalent of the'other in inductive effect :upon the re.-

peater from outward currents.

12. In atelephone repeater system, the

combinationof a divided or sectional main 'circuit sections, an independent repeaterreceiver for each circuit section at the repeater station, vtwo local or tertiary circuits for each repeater-rece1ver, fornnngan electrica'lor induction balance therefor, an in dependent. primary circuit --for each main line circuit section, having a source of enjergy-and a transmitter, and an induction coil 'for each main line circuit section, said coils having primary, secondary, and tertia-ry windings for; directly inductively associatingeach repeater receiver in its ter-- tiary circuit with its respective main line circu tsectlonand with the primary circuit of the opposite-repeater.

14'. In a telephonic repeating system, the combination of a mam line divided lntotwo independent circuit sections at a repeater station, a repeating device for each" p tron; two independent hne circuits associated main line section at the repeater station,

two tertiary circuits for each repeater de:

vice, a primary circuit for each repeater ,devlce, each oi. the ma n circuit sections and its respective primary circuit being ,in-

ductivcly connected with one of their respective tertiary circuits, thc othertertiary circuits being respectively inductively connected each -w1th their, respective primary circuits.

In a telephone repeater system, the combination of a main circuit section, tertiary. circuits, at primary circuitand a repeating device, induction coil windings, as-

in one division 01. each double tertiary.

sociating; said -ma-in circuit sections, a-,,tertlary circult, the primary clrcu-it, and the repeating device,th e induction coil secondary Winding inducing the inward'currentsfromthe line circuit into their associatedtertiary circuit and the primarycircult simultaneously, an induction c011 associating said primary circuit, a second tertiary circuitfand the repeating device,-the current induced into, said primary circuit being reinduced into the second-tertiary circuit bynieans of said last-mentioned induction coil, thecurrents in the two tertiary circuits coo crating in setting up the electro-magnetic e ectsfor the repeater-receiver to actuate said receiver.

16. In a telephone repeater system, the

combination of a main circuit section, -terand the repeating device, the local cur-rents.

in said primary circuit simultaneously, in-

ducing currents into the line circuit and into each of; the tertiary circuits to set up in the tertiary circuits opposing electromagnetic effects, and to setup or inductively transmit into the line circuit the reproduced currents, the opposing electro-m-agnetic cf fects rendering the repeating device inactive. 17. In a twin telephone repeater, the combination of two independent line 7 circuits,

a repeating device for each line circuit'each COIHPIISZIlg a. recelver and a -Ttransm1tter, a

primary circuit for each line circuit and lts repeater, each primary 10111311113 being di rectly lnductively connected with its-respective -line -circuit but controlled by and con;- nected with the transmitter of the opposite re'peatingdevice, two local or tertiary circuits for each repeating device, one of which tertiary circuits of each repea-til'ig device is directly inductively connected with its respective linecircuit and also with its re spective primary circuit, the other tertiary circuit of each repeatin device being directly but separately in uctively connected with its respective primary circuit,

In a telephonic repeater, in combinafor repeater service, two repeating devices, one for each respective line-circuit, each r peating device comprlslng a receiver and a transmitter, a winding in each line-circuit to control the respective repeating devices to actuate them by the inward or received-currents, a transmitting'or primary circuit for each repeating device, a balancing auxiliary or tertiarycircuit for each repeating device, divided circuit neutralizing means in each balancing circuit for each repeatingdevice,

one division of each neutralizing means being directly inductively connected with its respective line-circuit and with the trans:

mitting or primary-circuit of the opposite repeating device, and'thc other dlvision 01' each neutralizing means belng directly 111- ductively connected with the transmitting or primary-circuit only of the opposite repeatv 111g device.

19. In a reciprocal telephone repeating system, the combination, with twin repeaters at a repeating station in a main line circuit for the repeating of telephone transmission,

transmitter, each'primary circuit being inor tertiary circuits for each of the twin repeaters, by which twin circuits respectively {the repeaters are rendered inert to their repeated currents, two double circuit induc- 2 tion coils one for eachof the tw1n tertiar o 0 o a c n circuits, each double circuitinduction-coil "directlyinductively associating one of its respective tertiary circuits with a respective primary circuit for coiiperation in rendering therespective repeater inert to the repeated or outward currents, and also rendering it increasingly eflicient to received or inward line currents, the other ofthe respectlve tertiarycircuits forming the direct inductive association of the receiver of its respective repeater wlthqits respective line-circuit and with the associated rimary' circuit thI'OU h the re ective} trip 'ecircu1t induction-c011,-

' as and or the purpose set forth.

20,111 a reciprocaltelephone repeater system, thegcombination with two telephone linesfof two electro-magnetic receivers connected-inductively one with and for each of 45 saidglinespandw-two variable resistance tra ns= mittersl o erated by said receivers-and connected in uctively one with and for each of said lines, aaprimary or transmitting circuit for each 'ofiisaid transmitters, tertiary local circuits-' for each receiver and means within the'ter tjary'c rcults for neutralizing each "receiver to prevent. automatic reaction betWeenJthe lines by repeated currents,v and means for establishing all the said inductive connections for the receivers and transmitters directly and immediately with their '11 respective lines;

-" 21.111 areciprocal'te'lephone repeater s tom, the combination with two line circuits,

of' a repeater for each, a primary or reproducingrircuit. and .two tertiary or receiving circuits 'fonz each repeater,- one tertiary circuit-z of-g-ea'ch' repeater inductively directly connecting; the repeater with both its respective line circuit andth'e primary circuit of the other or associated" repeater, and the other tertiary circuit of each repeater being individually I directly inductively co'nnocte associated repeater.

22. In a telephone-current repeating and Irenewingfg system, the combination with a sectioua ly divided main telephone-circuit having terminal telephones, of one or more ers for reciprocal cooperation at each staeach repeater having its receiver operatively identified with but one respective line-circuit, and a current renewing local battery circuit for each repeater-transmitter ductively associatedwith-the next main cirthe two circuit-sections, local receiver-cirfor receiving, and at times 'difi'erentially to prevent operation, for each repeater, and means for. directly mductively associatmg circuit-section.

the combination with a line or main circuit which is separated or divided into repeating sections, 0 one or more-repeating stations on said main circuit, with two repeaters at sitized or polarized e ectro-magnetic receiver and a variableresistance transmitter, the transmitters being adapted to be actuated by their receivers by the received line-currents and to transmit their reproduced currents respective receivers sections, the two transmitters at any one station each being adaj t ed to transmit in an op osit'e direction to t ie other, also! of two local circuits for each receiver in which the; receivers'are connected in a manner to be balanced and neutral or inert to the local repeating currents, a line induction coil with secondary, tertiary and primary windings for each line section or reits secondary in the line, its tertiary in one of the balancing local circuits of each repeaterand its primary winding. in circuit peater-transmitter and a source of current, another induction-coil for each repeater, said coils having secondary and primary windings, with their secondary windings-ciii-the circuit of the other balancing local-circuit '24. In a reciprocal telephone current+retion with twoline circuits, of two teleph e repeaters each comprising a magnetich 1y sensitize electro-magnetic receiver and a repeater stations on said circuit, two repeatsaid circult belng directly and immediately incuit-section to transmit into but that one of cuits which jointly act cooperatively at times each repeater-circuit with its respective main 23.111- anautomatically reciprocal telephone current remforcer or repeater system,

a each station, each re eater comprising a senwith the transmitter of. the opposite re-,

respectively and the rimary windings also in the circuit with t e res ective opposite transmitter and its source 0 energy.

also with the primarycircuit of theother or tion, one repeater for each respective circuit,

into the main circuit section succeeding their" peaterat each station, each such coil having.

.p'eating and renewing system, the combina: I

transmission with only theot-he'r or. oppesite line circuit, a pairofctertiarv feircuits for each repeater adaptedfrespectL-vely to 00-.

operate n received eurrel jt,reflects to render the TGCBIVBIS, sens tive t.0 theeinwvard 11116 cur- 're'nts, a pair of primary elrcnif'slene f0re'ach J transmitter, means fp'r' 'directIy-- inductive1y connecting each.primarypircuit witl the 0pposite line circuit'and one of-the tertiary cir'-' cuits ef the cpposite repeater, and means for individl ally dlrectly inductively connectm .e'ach pr1mary circuit also vvith the secon tertiary circuit of the epposlte repeater, and

the primary repeated current flows being {adapted to produce diflerential' eifects in the separate intinctive .cqnnections to thereby renderitherepezttersinsensitive, and; efi'e'ctings; unidirectional reciprocal re-transmission in the lines. I NATHANIEL Gr. WARTH;

' NVitnesses: 'ALIGE 3. 000K, t

CHAs. S. :DRUGGAN, Y 

